A radio-frequency power amplifier that amplifies the power of a radio-frequency signal is provided in the front end of a mobile communication terminal, for example, and amplifies the power of a radio-frequency output signal. Such a radio-frequency power amplifier is described in Japanese Laid-Open Patent Publication No. 2005-123764, for example.
Japanese Laid-Open Patent Publication No. 6-258404 descries a digital integrated circuit that contains an on-chip oscillator circuit and outputs a radio-frequency signal in response to an external control signal.
A power amplifier amplifies an input signal in a predetermined frequency band requested by specifications to a predetermined amplitude (gain) requested by the specifications. Therefore, testing of the power amplifier involves inputting a radio-frequency input signal in a predetermined frequency band into the power amplifier to test the power of a radio-frequency output signal, test for a signal distortion, and measure current consumption.
During the testing, generally a radio-frequency test probe is connected to a wafer-level device to provide a radio-frequency input signal to the device and an amplified radio-frequency output signal is obtained through another test probe similar to the former.
However, the radio-frequency test probes are expensive. In addition, it is structure-wise difficult to test multiple device chips with many test probes at a time because the test probes need to be brought into contact with the device chips at the same time. The costly testing method leads to high prices of power amplifiers.